Using only long windows in MPEG-2/4 AAC encoding

The MPEG-2/4 AAC standard uses both long and short windows. However, using short windows complicates the implementation of encoders. In this paper, we propose a simple method to encode signals only with long windows. By setting all the scalefactors to be the same, the proposed approach is fully compatible to the standard. The objective experiments using PEAQ show that the proposed approach has a better coded quality at 64 kbps for mono music. Subjective listening experiments show that the proposed approach performs much better for coding mono music at a lower bitrate of 32 kbps. Therefore, the proposed approach is a promising alternative in coding transient signals without using short windows.